You have 6.75 sq. ft.

At an optimal level of 7000 Lumens per sq ft.... you need 47,000 lumens.

Your HPS at 1000W will provide about 140,000 lumen at 2 feet.

I suppose that could be over kill but since you are talking HPS I dont think you have an issue.

I really think you should consider a 500W MH and 500W HPS combo unit though. Yes you can grow from start to finsih with HPS but I just don't believe it will bring out the full potential of the plants.

They need blue spectrum lighting and the HPS just doesnt deliver enough of it.

Anyhow, in the unlikely event it stresses your crops, raise the lights further away and you'll be fine.

Just mine .02 for ya....

HAPPY GROWING